Discrete Element Method applied to the simulation of the stress state in granular materials

Abstract

This work examines the Discrete Element Method (DEM), also known as the particle method, for its application in soil mechanics, specifically to calculate the tension acting on granular materials without cohesion. First, theoretical aspects of soil mechanics and the physical properties of some types of granular materials are presented, and the material properties are used afterwards in numerical examples. Following this, the DEM formulation is described, corresponding to the force and movement equations acting on each particle. For that, Newton’s second law, the force–displacement law, Hertz’s contact law, and some concepts from particle mechanics are defined. The integration over time process and the numerical solution algorithm presented by T.I. Zohdi are also described. Additionally, a new optimisation process for contact detection is described, one which significantly diminishes computational costs and therefore analysis time. Finally, some basic physics examples necessary for the formulation validation and application in soil mechanics are presented. The results obtained with the software developed in this research are then compared with soil mechanics results, which are simulated using the GeoStudio software. The GiD program was utilised for graphical presentation of the results.